scholarly journals Characterization of Salmonella isolates from municipal sewage, patients, foods, and animals in Greece using antimicrobial susceptibility testing and pulsed field gel electrophoresis

2016 ◽  
Vol 2 ◽  
pp. 12-18 ◽  
Author(s):  
Theofilos Papadopoulos ◽  
Antonios Zdragas ◽  
Georgia Mandilara ◽  
Georgios Vafeas ◽  
Virginia Giantzi ◽  
...  
2013 ◽  
Vol 781-784 ◽  
pp. 1332-1335
Author(s):  
Tao Yu

Listeria monocytogenes isolates recovered from retail foods were characterized by serotyping, genotyping using pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing. Six serotypes were identified among the isolates and the predominant serotype was 1/2a (42, 48.8%). PFGE differentiated the 86 isolates into 23 ApaI restriction patterns. Twenty-five (29.1%) of the L.monocytogenes strains exhibited resistance to at least one antimicrobial. Resistance to ciprofloxacin (17.4% of the isolates were resistant) and resistance to tetracycline (17.4%) were observed frequently.


2016 ◽  
Vol 79 (8) ◽  
pp. 1418-1423
Author(s):  
M. FONTCUBERTA ◽  
R. PLANELL ◽  
A. TORRENTS ◽  
S. SABATÉ ◽  
R. GONZALEZ ◽  
...  

ABSTRACT The main purpose of this study was to determine the prevalence of Escherichia coli O157 on bovine carcasses before and after chilling at a large slaughterhouse located in the city of Barcelona, Spain, to assess the effectiveness of dry chilling on reducing E. coli O157 contamination of carcasses. In addition, the study characterized the E. coli O157 strains isolated in terms of virulence factors, antibiotic susceptibility, and their genetic diversity. Individual bovine carcasses were sampled before (n = 300) and after (n = 300) chilling over an 8-month period. Positive samples for E. coli O157 were subjected to virulence screening by PCR (stx1, stx2, and eaeA genes and the fliCH7 gene), antimicrobial susceptibility testing, and molecular typing by pulsed-field gel electrophoresis. A total of 9.7% (29 of 300) of the nonrefrigerated carcasses examined and 2.3% (7 of 300) of the refrigerated carcasses were positive for E. coli O157. All the isolates were serotype O157:H7, 92% (33 of 36) carried the stx1, stx2, and eaeA genes, and 8% (3 of 36) carried the stx2 and eaeA genes. Antimicrobial susceptibility testing showed a high degree of resistance: 29 strains (81%) were resistant to at least 1 antimicrobial of the 12 antimicrobials tested; 69% (25 of 36) were resistant to 4 or more antimicrobials. Molecular typing by pulsed-field gel electrophoresis found a high diversity of genetic types, implying little cross-contamination in the slaughterhouse. This study confirms that E. coli O157:H7 is present on the carcasses slaughtered in Spain, although its prevalence is reduced by the dry chilling process used. The recovered isolates showed potential pathogenesis and a high degree of multidrug resistance, confirming the importance of bovine meat monitoring.


2006 ◽  
Vol 72 (4) ◽  
pp. 3046-3049 ◽  
Author(s):  
Qiongzhen Li ◽  
Jerod A. Skyberg ◽  
Mohamed K. Fakhr ◽  
Julie S. Sherwood ◽  
Lisa K. Nolan ◽  
...  

ABSTRACT Seventeen Salmonella enterica serovar Hadar isolates recovered from bison were found to possess a range of virulence genes and resistance to tetracycline, gentamicin, sulfamethoxazole, and streptomycin simultaneously. A 1-kb class 1 integron containing the aadA1 gene was identified in all isolates. Pulsed-field gel electrophoresis found that all isolates were closely related, indicating the possibility of cross-contamination during processing.


2017 ◽  
Vol 71 (1) ◽  
pp. 0-0
Author(s):  
Patrycja Zalas-Więcek ◽  
Tomasz Bogiel ◽  
Krzysztof Wiśniewski ◽  
Eugenia Gospodarek-Komkowska

Introduction: The aim of the study was to evaluate genetic relatedness and antimicrobial susceptibility of extended-spectrum beta-lactamase-producing E. coli strains isolated from patients hospitalized in the University Hospital in Bydgoszcz (Poland).Material and methods: The study included 33 extended-spectrum beta-lactamase-producing E. coli strains isolated from 31 patients. The chromosomal DNA was extracted from the strains and separated by pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was performed by the agar dilution method and carried out according to the European Committee on Antimicrobial Susceptibility Testing recommendations.Results: According to the pulsed-field gel electrophoresis results, 32 distinct pulsotypes were revealed. Based on Molecular Analyst Fingerprinting software analysis, the studied isolates were divided into four subgroups: 6 (18.2%) isolates showing similarity greater than 90% (group A); 19 (57.6%) showing 80-90% similarity (group B); 7 (21.2%) showing 70-79% similarity (group C); and one isolate with less than 70% similarity (group D). Among E. coli isolates showing similarity greater than 90%, four antimicrobial patterns were noted. Among the isolates showing 80-90% similarity, 18 antimicrobial patterns were observed. E. coli isolates showing 70-79% similarity presented 6 antimicrobial patterns.Conclusions: Our results show a high degree of genetic diversity of extended-spectrum beta-lactamase-producing E. coli isolates. However, based on a similarity of ≥80%, almost 75% of E. coli isolates were clonally related. Although it is difficult to identify definitive transmission events based on the recovery of indistinguishable pulsed-field gel electrophoresis types alone, we speculate that extended-spectrum beta-lactamase-producing E. coli strains may have disseminated throughout the hospital.


2006 ◽  
Vol 51 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Ewa Sadowy ◽  
Radosław Izdebski ◽  
Anna Skoczyńska ◽  
Paweł Grzesiowski ◽  
Marek Gniadkowski ◽  
...  

ABSTRACT β-Lactams are the drugs of choice for the treatment of infections caused by the important bacterial pathogen Streptococcus pneumoniae. The recent growth of resistance of this organism to penicillin observed worldwide is of the highest concern. In this study, using 887 surveillance pneumococcal isolates recovered in Poland from 1998 to 2002, we observed the increase in penicillin nonsusceptibility from 8.7% to 20.3%. All of the 109 penicillin-nonsusceptible S. pneumoniae (PNSP) isolates identified, together with 22 archival PNSP isolates from 1995 to 1997, were subsequently analyzed by susceptibility testing, serotyping, profiling of pbp genes, pulsed-field gel electrophoresis, and multilocus sequence typing (MLST). Four predominant serotypes, serotypes 6B, 9V, 14, and 23F, characterized 85.5% of the isolates. MLST revealed the presence of 34 sequence types, 15 of which were novel types. Representatives of seven multiresistant international clones (Spain23F-1, Spain6B-2, Spain9V-3, Taiwan23F-15, Poland23F-16, Poland6B-20, and Sweden15A-25) or their closely related variants comprised the majority of the study isolates. The spread of Spain9V-3 and its related clone of serotype 14/ST143 has remarkably contributed to the recent increase in penicillin resistance in pneumococci in the country.


2002 ◽  
Vol 64 (3) ◽  
pp. 237-243 ◽  
Author(s):  
Yoshihisa WAKITA ◽  
Akira SHIMIZU ◽  
Václav HÁJEK ◽  
Junichi KAWANO ◽  
Kenji YAMASHITA

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